摘要 |
The mean value of the amplitude of analog signals appearing on individual control paths is continuously formed. Three-level switch means are provided which are addressed by groups of two control path voltages of the individual control paths, and a disturbed control path is disconnected by the switch means, and either the output signal of the mean-value forming unit or one of the remaining connected input signals is weighted, so that failure of one control path does not significantly affect the output signal of the mean-value forming unit which is supplied to following apparatus. Thus, the failure of a control path can occur without interruption or significantly changing the operation of this supervisory apparatus. This failure can sound an alarm which pinpoints the specific location of the fault. |